Powered wheelchair for beach terrain

Abstract

A powered wheelchair for beach terrain is provided that includes a an occupant seat assembly mounted to a frame that has an electric drive system with a pair of electric motors mounted thereto. A hand grip support frame is coupled to a rear end of the frame. The electric drive system is drivingly coupled to at least two of a plurality of wheels rotatably mounted to the frame. The powered wheelchair includes a portable power source and a control system mounted to the main frame. The control system is electrically coupled to the portable power source and the electric drive system. The control system has a first set of operating controls disposed in proximity to the occupant seat assembly and a second set of operating controls disposed in proximity the hand grip support frame for switch selective operative control of the powered wheelchair.

What is being claimed is: 
     
       1. A powered wheelchair for beach terrain, comprising:
 a frame assembly including a longitudinally extended main frame and a hand grip support frame extending from an end of said main frame in a direction transverse with respect to the longitudinal direction of said main frame; 
 an occupant seat assembly mounted to said main frame; 
 an electric drive system mounted to said main frame; 
 a plurality of wheels rotatably coupled to said main frame, at least two of said plurality of wheels on opposing sides of said main frame being drivingly coupled to said electric drive system; 
 a portable power source mounted to said main frame; and 
 a control system mounted to said main frame and electrically coupled to said portable power source and said electric drive system, said control system including a first set of operating controls disposed in proximity to said occupant seat assembly for use by an occupant thereof and a second set of operating controls disposed in proximity to said hand grip support frame for use by an assistant operator, said second set of operating controls including a pair of single axis thumbwheel controls respectively positioned adjacent a pair of hand grips coupled to said hand grip support frame to be operable by the assistant operator while said pair of hand grips is being held by the assistant operator. 
 
     
     
       2. The powered wheelchair of  claim 1 , where said control system includes a control processor and a switch coupled to said control processor for selectively enabling only one of said first and second sets of operating controls. 
     
     
       3. The powered wheelchair of  claim 1 , where said control system includes an emergency stop circuit operated by either of a first emergency stop switch disposed in proximity to said occupant seat assembly for use by the occupant and a second emergency stop switch disposed in proximity to said hand grip support frame for use by an assistant operator. 
     
     
       4. The powered wheelchair of  claim 1 , where said electric drive system includes a pair of electric motors, each of said pair of electric motors being drivingly coupled to at least one of said plurality of wheels on one respective side of said main frame by a chain and sprocket transmission. 
     
     
       5. The powered wheelchair of  claim 1 , further comprising a pair of hand grips coupled to said hand grip support frame in laterally spaced relationship and extending from said hand grip support frame in a substantially vertically downward direction. 
     
     
       6. The powered wheelchair of  claim 1 , where each of said pair of single axis thumbwheel controls is coupled to said control system to control both speed and rotational direction of a respective one of said pair of electric motors, whereby wheelchair speed is controlled by operating said single axis thumbwheel controls in unison and steering of said wheelchair is effectuated by operating said single axis thumbwheel controls differentially. 
     
     
       7. The powered wheelchair of  claim 1 , where a first of said pair of single axis thumbwheel controls is coupled to said control system to control speed of said pair of electric motors selectively in either of two opposing rotational directions to propel the powered wheelchair forward or backward, the second of said pair of single axis thumbwheel controls being coupled to said control system to control a turning radius of the powered wheel chair, the control system controlling the speed of the pair of electric motors differentially to thereby affect steering of the wheelchair responsive to displacement of an actuator of said second single axis thumbwheel control. 
     
     
       8. The powered wheelchair of  claim 1 , where said portable power source includes a pair of batteries interchangeably mounted to said main frame, only one of said pair of batteries being electrically coupled to said control system for powering said control system and said electric drive system through said control system, the other of said pair of batteries serving as a spare to alternately be connected to said control system. 
     
     
       9. The powered wheelchair of  claim 1 , where said electric drive system includes a pair of electric motors, each of said pair of electric motors being drivingly coupled to a pair of said plurality of wheels on one respective side of said main frame by a chain and sprocket transmission. 
     
     
       10. The powered wheelchair of  claim 1 , where said plurality of wheels is defined by two pairs of drive wheels rotatably coupled to said main frame, each pair of said two pairs of drive wheels being on a respective one of said opposing sides of said main frame, said electric drive system includes a pair of electric motors, each of said pair of electric motors being drivingly coupled to a respective pair of said two pairs of drive wheels and thereby forming a four wheel drive system. 
     
     
       11. A powered wheelchair for beach terrain, comprising:
 a frame assembly including a main frame and a hand grip support frame extending substantially vertically upward from a rear end of said main frame, said hand grip support frame including a horizontal frame member; 
 an occupant seat assembly mounted to said main frame adjacent a front end thereof; 
 a plurality of wheels rotatably coupled to said main frame on two opposing sides thereof; 
 a pair of electric motors mounted to said main frame, each of said pair of electric motors being drivingly coupled to at least one of said plurality of wheels on one respective side of said main frame; 
 a portable power source mounted to said main frame; and 
 a control system mounted to said main frame and electrically coupled to said portable power source and said pair of electric motors, said control system including a first set of operating controls disposed in proximity to said occupant seat assembly for use by an occupant thereof and a second set of operating controls disposed in proximity to said hand grip support frame for use by an assistant operator, said control system further including a motor drive circuit for each of said pair of electric motors and an emergency stop circuit, said emergency stop circuit is initiated to electrically disconnect said portable power source from said motor drive circuits responsive to detection of either of a manual operation of at least one emergency stop switch or detection of a failure of either of said motor drive circuits, said initiation of said emergency stop circuit activates dynamic braking of said pair of electric motors. 
 
     
     
       12. The powered wheelchair of  claim 11 , where said control system further includes a control processor and a switch coupled to said control processor for selectively enabling only one of said first and second sets of operating controls. 
     
     
       13. The powered wheelchair of  claim 11 , where said emergency stop circuit includes a first emergency stop switch disposed in proximity to said occupant seat assembly for use by the occupant and a second emergency stop switch disposed in proximity to said hand grip support frame for use by an assistant operator, said emergency stop circuit being initiated by operation of either of said first emergency stop switch or said second emergency stop switch. 
     
     
       14. The powered wheelchair of  claim 11 , further comprising a pair of hand grips coupled to said horizontal frame member in laterally spaced relationship and extending from said horizontal frame member in a substantially vertically downward direction. 
     
     
       15. The powered wheelchair of  claim 11 , where said second set of operating controls includes a pair of single axis thumbwheel controls respectively positioned adjacent a pair of hand grips to be operable by the assistant operator while the pair of hand grips is being held by the assistant operator. 
     
     
       16. The powered wheelchair of  claim 15 , where each of said pair of single axis thumbwheel controls is coupled to said control system to control both speed and rotational direction of a respective one of said pair of electric motors, whereby wheelchair speed is controlled by operating said single axis thumbwheel controls in unison and steering of said wheelchair is effectuated by operating said single axis thumbwheel controls differentially. 
     
     
       17. The powered wheelchair of  claim 15 , where a first of said pair of single axis thumbwheel controls is coupled to said control system to control speed of said pair of electric motors selectively in either of two opposing rotational directions to propel the powered wheelchair forward or backward, the second of said pair of single axis thumbwheel controls being coupled to said control system to control a turning radius of the powered wheel chair, the control system controlling the speed of the pair of electric motors differentially to thereby affect steering of the wheelchair responsive to displacement of an actuator of said second single axis thumbwheel control. 
     
     
       18. The powered wheelchair of  claim 11 , where said portable power source includes a pair of batteries interchangeably mounted to said main frame, only one of said pair of batteries being electrically coupled to said control system for powering said control system and said electric drive system through said control system, the other of said pair of batteries serving as a spare to alternately be connected to said control system. 
     
     
       19. The powered wheelchair of  claim 11 , where said pair of electric motors are each drivingly coupled to a pair of said plurality of wheels on one respective side of said main frame by a chain and sprocket transmission. 
     
     
       20. A powered wheelchair for beach terrain, comprising:
 a frame assembly including a main frame; 
 an occupant seat assembly mounted to said main frame adjacent a front end thereof; 
 two pairs of drive wheels rotatably coupled to said main frame, each pair of said two pairs of drive wheels being disposed on a respective one of two opposing sides of said main frame; 
 a pair of electric motors mounted to said main frame, each of said pair of electric motors being drivingly coupled to a respective pair of said two pairs of drive wheels and thereby forms a four wheel drive system; 
 a portable power source mounted to said main frame; and 
 a control system mounted to said main frame and electrically coupled to said portable power source and said pair of electric motors, said control system including a speed and direction control disposed in proximity to said occupant seat assembly for use by an occupant thereof and a motor drive circuit for each of said pair of electric motors said control system further includes a first emergency stop switch disposed in proximity to said occupant seat assembly for use by an occupant thereof, said control system further including an emergency stop circuit, said emergency stop circuit being initiated to electrically disconnect said portable power source from said motor drive circuits responsive to detection of either of a manual operation of said emergency stop switch, a failure of said speed and direction control or detection of a failure of either of said motor drive circuits, said initiation of said emergency stop circuit activates dynamic braking of said pair of electric motors. 
 
     
     
       21. The powered wheelchair of  claim 20 , where said portable power source includes a pair of batteries interchangeably mounted to said main frame, only one of said pair of batteries being electrically coupled to said control system for powering said control system and said pair of electric motors through said control system, the other of said pair of batteries serving as a spare to alternately be connected to said control system. 
     
     
       22. The powered wheelchair of  claim 20 , where said frame assembly further includes a hand grip support frame extending substantially vertically upward from a rear end of said main frame, said hand grip support frame including a horizontal frame member and a pair of hand grips coupled to said horizontal frame member and extending therefrom in a substantially vertically downward direction. 
     
     
       23. The powered wheelchair of  claim 22 , where said control system further includes a pair of single axis thumbwheel controls respectively positioned adjacent said pair of hand grips to be operable by an assistant operator while holding he pair of hand grips. 
     
     
       24. The powered wheelchair of  claim 23 , where said control system further includes a control processor and a switch coupled to said control processor for selectively enabling only one of said speed and direction control and said pair of single axis thumbwheel controls. 
     
     
       25. The powered wheelchair of  claim 20 , where said frame assembly further includes a hand grip support frame extending substantially vertically upward from a rear end of said main frame, said hand grip support frame including a horizontal frame member and a pair of hand grips coupled to said horizontal frame member and extending therefrom in a substantially vertically downward direction, and aid control system further includes a pair of single axis thumbwheel controls respectively positioned adjacent said pair of hand grips to be operable by an assistant operator while holding he pair of hand grips. 
     
     
       26. The powered wheelchair of  claim 25 , where said control system further includes a second emergency stop switch disposed in proximity to one of said pair of single axis thumbwheel controls, said emergency stop circuit being initiated by operation of either of said first emergency stop switch or said second emergency stop switch.